• t * ■ ^1 BOUGHT WITH THE INCOME PROM THE SAGE ENDOWMENT FUND THE GIFT OP X89X ytyini.. Cornell University LIbrery arV18758 Diseases of the air brake system. 3 1924 031 277 084 olin.anx The original of tiiis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924031277084 DISEASES Air Brake System THEIR CAUSES, SYMPTOMS AND CURB PAUL SYNNESTVEDT 1E;f(iv& 3EOI«oit Chicago The W. F Hall Feinting Compant 1896 COPTKIGHT, 1894 By PAUL SYNNESTVEET All; EIGHTS EESEKVKD CONTENTS. Page Pump 9 Governor. 23 Main Drum 35 Engineer's brake Vai Plate 11, Fig. 8 Diseases of the Air Brake System. 53 pressure in the cavity D will not reduce with suificient rapidity through the small preliminary exhaust port if aii is leaking from the main drum into the cavity at the same time. To go back now to the increase of pressure in the train-pipe. This may be due to trouble with the feed-valve. It is possible it may not be properly adjusted, or if it is all right in that respect it may be found to seat imperfectly. This may be due to some bend or defect of a similar na- ture in the small spindle of the valve (63) or possibly merely dirt on the seat of this valve. In a case of this nature it is hard to determine which is the most promis- ing field to investigate first. If in service application the reduction in cavity HD is found to be slower than it should be, the trouble is probably in the gasket, but if this symptom is not present at all, it is a reasonable supposi- tion that the gasket is all right, and something else must be examined instead. BLOW FROM EXHAUST WHEN HANDLE IS PUT TO RUN- NING OR RELEASE POSITION. An excessive blow out of the train-pipe exhaust port on a lone engine or very short train (one or two cars) when the handle is moved to running or release position after applying the brakes, is no cause for alarm unless it be very extreme, as it is simply due to the fact that the train-pipe fills more quickly than the cavity 'D because the ports are larger, and until the pressure on top of the equalizing piston becomes greater than that beneath it, 54 Diseases of the Air Brake System. such a blow must be the natural result. - This blow will stop more quickly if the handle be thrown immediately to full release position in letting off the brakes than if merely moved to running position, as, in the former case, the cavity (D) then has the benefit of an additional port {e) through which it may fill, while the release opening is not as much greater in proportion. If the piston refuses CO close the exhaust in a reasonable time it should be iaken out and thoroughly cleaned. BUNNrNG POBTTTCrN" ^ It/att^g, -Erti/r'fl,,iV.\K. Diseases of the Air Brake System. 57 Now York Engineers' Valve — Plates ig and i6. This valve, as well as the two of which we have pre- viously treated, has the three principal positions of the old three-way cock; "release," for letting the air from the drum back into the train; "application" for shutting off the drum and exhausting the air from the train to the atmosphere; and "lap," which closes all communication either way. BLOW FROM EXHAUST. If there is a blow out of the exhaust when the handle is in the release position, or on "lap," valve 42 is the offending part, and must be examined to ascertain whether it seats properly and if the seat is tight.. If the pressure in the train-pipe constantly increases while the handle stands on "lap," the connections controlling com- munication from the drum to the train must be investi- gated. These are the piston(32)and the valves(64 and 70). The piston is balanced between drum pressure below and train-pipe pressure above, and if the packing rings are not perfectly tight, the pressure in the train with the han- dle on the "lap" will soon show a gain on the gauge when the engine has no cars attached, or in other words, only a short pipe connected. This leakage can be reduced to a minimum by keeping the leather (73) soft and pliable. RELEASE OF BRAKES. Releasing of brakes on the lone engine will be apt to be one of the results of any leakage from the drum into the train, and an examination of the engineer's valve should be made before blame is laid on the triple. 58 Diseases of the Air Brake System. In case of failure of the exhaust from the train to open fully when the handle is put to the emergency position, attention should be given immediately to the spring (33) , as a weakening, displacement or breaking of this spring would cause such defective action. Diseases of the Air Brake System. 59 TRAIN-PIPE. In speaking of the tram-pipe we include all the piping which serves to carry the air from the engineer's valve to the triple-valve throughout the train. Not the pipe that carries the air from the triple-valve to the reservoir; as that must properly be regarded as a part of the reservoir. Of course, the hose connections form a part of the train- pipe, as do also the branch pipes leading from the train- pipe to the triple-valves, and on passenger trains the small length of pipe leading to the conductor's valve. The two great difficulties that arise in the train-pipe are leakage and stoppage, either of which, but the latter particularly, may be productive of the most serious con- sequences. Leakage. Leakage may most readily be detected by a continued falling of the black pointer on the gauge when the en- gineer's valve is placed on the lap, and the rapidity of the reducti9n will show the extent of the leak. A very heavy leak will make it difficult, or, in some cases impossible, to maintain sufficient pressure in the train to properly operate the brakes, while a slight leak will sometimes cause a sticking of the brakes, though serious trouble from this cause may be prevented on the 60 Diseases of the Air Brake System. road if the pump be in good condition and the brakes carefully handled, as the constant feeding of pressure back from the engine will overcome the loss. Slight leak- age on trains running on mountain grades is more serious, because it results in a constant increase of the braking force when it is not wanted. LOCATING LEAKS. If the engine gauge shows a leak in the train -pipe a careful examination of the following points should be made, as they are the places where it is most likely to occur: Hose couplings, hose, pipe unions under the tender, conductor's valves, and the T at which the conductor's valve branch pipe is connected to the main pipe. A bleeding cock left open on any auxiliary reservoir or a triple-valve blowing from the exhaust will also show as a leak in the train-pipe (that is, by a reduction or falling of the black pointer on the gauge). These cases, however, are very easy to find, because they make a very decided and audible blow at one point. The T connection, where the conductor's valve branch pipe is connected to the main train-pipe, is particularly mentioned because that is a joint frequently broken by pulling cars apart without uncoupling the hose. LEAKAGE IN COUPLINGS. Perhaps the most frequent cause of leakage is to be found in the hose couplings, generally from some defect in the rubber packing ring. A leak at this point should be treated as follows: First uncouple the hose, examine the packing rubber, straighten it if it seems bent or Diseases of the Air Brake System. 61 twisted, and couple up again. If this does not help, and there is no time to replace the hose or packing rubber, take a little nail or wooden wedge and drive it in between the lugs on the coupling in such a way as to force the packing rubbers closer together in the position indicated at 2 in Plate 16 A. A very bad leak may sometimes be entirely stopped in this way. Never strike the lugs on the coupling so as to make it go together more tightly, as this makes it difficult to couple to a coupling which has a new rubber in it, and also increases the liability of rupt- uring the hose in case the train pulls apart. BURST HOSE. About the only remedy for hose which are burst or leaking is to replace them with good ones. If no extra ones are to be had one can be taken off from a car near the rear of the train, say the last hose on the last car. LEAKS UNDER THE TENDER. The pipe unions under the tender are a frequent cause of leakage, probably because of the conditions surround- ing them. Engineers should be very careful to thoroughly examine the equipment on their engines before condemn- ing the train crew for not stopping leaks which may be bothering them. It may be nothing more than a rotten gasket in one of the unions or a loosening of the nut because the pipe has been insecurely fastened and rattles. Too much emphasis cannot be put upon the desirabilitj'- of having all air-brake- pipes very '.securely and firmly fixed in place. This will prevent a great deal of trouble. ■'7r''TTr(fir,M,,,\ /m j:iiil}}lilllllf. r •"">""■■'■ Plate 16 A. 17- n ^ Plate 10 B. (62) Diseases of the Air Brake System. 63 LEAKAGE IN CONDUCTOR'S VALVES. Conductor's valves sometimes get to leaking because of dirt lodging in them. Sometimes (and always with the new style) they do not close after having been opened, and although the blow from such a one be heavy it may be hard to find, because the location of the valve in the closet renders it rather inaccessible. Stoppage, i. e. Obstruction. Now we come to the consideration of the second part under this head — stoppage. By this we refer to any obstruction which interferes with the passage of air through the pipe. This difficulty is always manifested by a refusal of the brakes to set or release properly back of a certain point in the train, while all those forward of that point operate satisfactorily. Sometimes the stoppage is of such a nature as to allow the air to pass freely through the pipe in one direction but not in the other, the obstruc- tion closing the pipe just like a valve. It will be very readily seen that this is a very danger- ous disease and may result in the death of the patient (total failure of the brakes at a critical time), if it is not very promptly treated and cured. Of course the closing of a hose-cock somewhere in the train is the most frequent form of this trouble, and great care must be taken at all times to see that this does not occur, or if it does happen, to have it immediately located and remedied. Hose-cocks will sometimes close while running if they stand in such a way as to strike against one of the timbers above the handle. 64 Diseases of the Air Brake Sysiem. TESTING BRAKES. The engineer can make a very close approximate test of the number of cars cut in from the engine back while he is running as well as when the train is at rest, without in any way interfering with the speed or momentum ol his train, by simply moving his engineer's valve handle from the running to the release position after his main drum ha" accumulated 20 pounds of excess pressure (red pointer 20 pounds higher than the black one), and care- fully noting the number of pounds that the red pointer falls during the first couple of seconds. For ten average freight cars it will fall about 10 pounds. For twenty cars or over it will fall fall from 15 to 18 pounds. If the train is cut out one or two cars back of the engine the reduction will be but a couple of pounds. This result will, of course, vary slightly with leakage, the size of the drum and the length of the cars, but a little practice will enable anyone to make a very close guess. If the obstruction in the pipe is of such a nature that it permits the passage of air in one direction but not in the other, it is apt to be still more dangerous. This has been known to occur through a curling up of the inside lining of the hose, the rubber rolling up into a ball, and, just like a valve, opening one way and closing the other. It might also be caused by the cylindrical screen in the car drain-cup collapsing or clogging up with dirt. Plate 16b, taken from the Rail- way Age, shows one that was in the possession of Mr. G. W. Rhodes. It is a fair sample of many that are now in service. Diseases of the Air Brake System. 65 Cases are also recorded where ice has been formed in the coupling or hose sufficient to obstruct the passage. This often results from allowing the hose to hang down and drag through the snow, and afterward coupling it without examination. Diseases of the Air Brake System. 67 AUXILIARY RESERVOIR. It is not generally supposed that anything ever goes wrong with the auxiliary reservoir, as it is nothing but a storage tank for air. It plays a very important part, however, in the action of the triple valve, and any leakage here, even though very slight, may seriously interfere with the functions' of the most vital mechanism of the brake. Except in so far as such leakage will cause a slight drain on the pressure in the train-pipe, any trouble with the auxiliary reservoir is purely local, however, and affects only the one car in the train. Since the freight and passenger reservoirs are of different construction, we shall have to consider them separately. PASSENGER ' 'AUXILIARY. ' ' The arrangement for quick-action brake on passenger cars is one which nearly all railroad men are familiar with. There are only two points on this reservoir liable to leakage: the bleeding cock in the bottom and the pipe which leads from the triple- valve to the reservoir; for, as was said some time before,. this pipe must be regarded as a part of the reservoir proper, being always open to res- ervoir pressure. 68 Diseases of the Air Brake System. Any leak at these points makes the brake slow to act, especially in service or graduation applications. Snch a brake will be the last to set and the first to release. On pafsenger cars equipped with the old automatic brake the triple-valve is suspended by a bracket from the reservoir, and this makes the nipple connecting the triple and the reservoir very liable to rupture at the thread. FREIGHT "auxiliary." The arrangement of freight brake is shown on Plate 18a. I/cakage here is most liable to occur through the bleed- ing cock (release valve) shown on top of the reservoir; from the reservoir into the, pipe (V) leading from the triple-valve to the cylinder, or most frequently of aU, across the gasket joint between the reservoir and triple- valve (15) at the narrow bridge between the opening to the reservoir and the cylinder pipe. In the two last cases the leak will show as a blow out of the triple-valve exhaust, which should not always be attributed to some defect in the t'iple valve itself.' Diseases of the Air Brake System. 69 BRAKE-CYLINDER While there are .several dififerent styles of brake cylinders, the arrragement of packing leather and piston head is practically the same in nearly all of them. For this reason we shall first consider that part and the pecul- iar ills to which it is heir. A section of a cylinder and piston is clearly shown in Plate 18a. CYLINDER LEAKS. Leakage by the piston may occur through dry packing leather (7), a leather badly worn or imperfectly fitted, or some defects in the follower-plate (6), or the bolts (5) which hold it in place. If the leak is in any of these places it will produce a blow out of the vent hole x, in the back cylinder head while the brake is set. Where the leather is to blame, plenty of good oil well distributed is the very best remedy. This softens the leathers and keeps them tight. A thorough cleaning occasionally, also, has a very beneficial effect, though in most cases leather packing will remain tight in spite of dirt if it is well lubricated. Sometimes, although rarely, a leak occurs at the joint between the cylinder and front cylinder head (that near- est the triple-valve) , and this may require a renewal of the gasket or possibly nothing more than a tightening of ^he bolts (14). 70 Diseases of the Air Brake System. The result of the above difficulties will be to cause the brake to come off more or less slowly without any release or blow from the exhaust or triple-valve. "sticking" of brakes. Sometimes a brake will remain ' 'stuck' ' after the triple- valve has released, and can only be pried back with a bar. This may be due to the release spring (9) being weak or broken, or most frequently, on freight cars, at least, to a binding because of lack of oil. Sometimes the sleeve- piston (3) gets so corroded as to stick fast in the back head. When brakes remain set after the triple-valve has released, a careful examination of the levers and rods should be made to see that they do not catch at any point. For "sticking of brakes" when the triple-valve does not release, see the following chapter. Diseases of the Air Brake System. 71 THE TRIPLE-VALVE. (Plates 17, 18, 19, 20 and 21.) There is probably no complaint more common amongst trainmen and engineers than ''The triple-valve sticks." It is safe to say that in nine out of ten cases where this complaint is made the triple-valve is not to blame at all. It is inerely the index which shows a defect somewhere else in the apparatus, for the triple-valve being the auto- matic part of the brake, the foundation of the whole system, is the first part to be affected when anything else gets out of order. In quite an extended experience with air brakes the author does not remember more than a few cases where triple -valves were so defective as to be absolutely inoperative. They must be in very bad shape indeed if they will not work at all. , ' BRAKE WIIvL NOT SET. In case the triple-valve refuses to act, the first thing to examine is the auxiliary reservoir, as that may not have its full supply of air and, of course, as it is the air in the auxiliary reservoir that moves the triple-valve piston, a deficiency of pressure there will prevent the valve from acting. Sometimes the bleeding cock will be found left open or leaking, and sometimes there is a leak some- where else about the reservoir of sufiBcient extent Diseases of the Air Brake System. 73 to prevent the proper accumulation of pressure. All the pipe connections about the reservoir should be very carefully examined. In case the reservoir contains considerable pressure it is of course useless to look for leaks, and the attention must be turned elsewhere. DIRT IN STRAINER. The strainer (Plate 17, No. 16) where the train-pipe connection is made should next be examined, as it some- times becomes completely stopped with dirt. Strainers in this condition are shown on Plate 18^. They were taken from actual service. They may be in such condition that they will permit sufficient air to filter through to partially fill the reservoir after a considerable length of time, and yet not allow the pressure to escape fast enough from the train-pipe side of the triple-valve to cause the brake to set. If there be plenty of air in the reservoir, and all the passages" are found to be free and open, the only remaining inference is that the main piston itself is "stuck," and this should then be taken out and cleaned. FROZEN TRIPLES. In very cold weather there is always the possibility that the valve may be frozen, especially if it is on a car near the head of the train and the main drum on the engine has much water in it. The author has located more than one negligent engineer, with his main drum half full of water, by discovering an excess of moisture in the triple- yalye under the baggage car which he pulled regularly, Diseases of the Air Brake System. 75 BLOW FROM EXHAUST. If there is a constant blow out of the exhaust of the triple-valve (or the pressure-retaining valve which is con- nected to the triple-valve exhaust) the first thing to deter- mine is whether it comes from the train-pipe or auxiliary reservoir. This can be very easily done by cutting out the valve with the cut-out cock. If the blow does not stop for some time and then grows fainter gradually, there is little question but that it comes from the reservoir, but if it stops immediately and the brake sets, it is a clear indication of a leak from the train-pipe, between the triple-valve piston and the cut-out cock, the reduction on the train-pipe side of the piston causing the application of the brakes. If the leak is found to be from the reservoir, it must come either from an imperfect fit of the seat of the slide-valve, or more probably from leakage past the narrow bridge that divides the reservoir and cylinder pas- sage in the gasket between the triple-valve and the part of the apparatus to which it is attached, it being fastened to the cylinder head on passenger cars and directly to the reservoir on freight equipments. If the blow be from the train-pipe it is nearly always due to an imperfect seating of the emergency valve (Plate 17, No. 10), the bearing face of which being rubber will sometimes rot out from the action of oil. In many cases a little dirt under this emergency-valve will cause a sharp blow out of the exhaust, and this can frequently be dis- lodged by a number of emergency applications of the brake, the rush of air into the cylinder blowing the dirt along with it. % ^KBKS^WKKBt tL ^^ysHH^IHs^v^Cffi . XX N \ \ \ ^ X S XX ^ XX \ X '7. XX Xx Mix XX X X <^ XX ^MN PIPE Plate 20. Diseases of the Air Brake System. ' 106 One noticeable thing about this valve was that on short trains it did not blow from the service exhaust when the handle was thrown to release position, the reason, for which will be obvious on a moment's study. Old Style Governor. Plate 29 is a sectional view of a pump governor many hundred of which are still in use, and which for conven- ience we shall call the "Old Style Governor." They were never very satisfactory, and in fact, but very few of those coming under the writer's personal observation were of any value at all. They were defective in theory and consequently a total failure in practice. The major- ity of them never would stop the pump at all. In oper- ation they depended to a certain extent on back pressure from the pump, acting upwards on valve 10, and of course as soon as this back pressure disappeared, nothing remained to hold valve 10 shut. It seems reasonable to suppose that if a good stiff spring were substituted for the spindle 9 (which is entirely superfluous) the spring being so arranged as to exert an upward pressure on valve 10, the device could be made to work. The author makes this suggestion for some of his readers to try. Another remedy, prescribed by Mr. Woods, of the C. & N.-W. Ry. at West Chicago, and successfully applied to quite a number of engines under his charge, is to substitute for the spindle 9 a stem and piston, the piston working in a cylinder screwed in in place of the stuffing box 2, and having its lower side connected with the exhaust pipe 6 by means of a small copper tube. With this arrangement, as soon as the air 106 • Diseases of the Air Brake System. pressure unseated the valve 13 the steam from the exhaust pipe flowed around and against the under side of the piston and forced the valve 10 to its seat. Of course in making such experiments it will be necessary to see that the rest of the apparatus is in proper shape. The cup piston on the end of valve 10 must be a good snug fit, the small spring 12 must be sufficiently long and stiff to readily seat valve 13, and valve 13 itself must be short enough to rest squarely on its seat, and still have a small space between its upper end and the diaphragm plate. Particular attention must be given to the last named point because, as will be readily seen, no pressure can be accumulated through port C, on top of valve 10 to open it, unless valve 13 is shut. Diseases of the Air Brake System. 107 APPENDIX. The plates shown under this head are from photographs of various parts of the air-brake apparatus in a diseased condition. Most of them were obtained through the kind- ness of Mr. G. W. Rhodes, superintendent motive power, C. B. & Q. R. R., but the author's thanks are also due to a number of others, who generously assisted him in making the collection. Plate 30. The first of the set shows an upper valve chamber bushing, taken from an 8-inch pump, together with a number of disabled air-valves. No. 1 is broken in a man- ner not at all uncommon, and yet one which, when it occurs in a lower discharge-valve of a 6-inch pump, is very apt to deceive the "doctor," for when he touches it underneath it feels all right, has the proper lift, etc. No. 2 has the head broken loose from the wings and forming a kind of collar around the stem or projection above. Nos. 3 and 4, as will be readily seen, are each broken in two pieces. The projecting knob on top of Diseases of the Air Brake Svstem. 109 No. 3 being missing entirely. This knob when broken off frequently wears round, like a little marble, and some- times causes trouble by getting stuck somewhere in some pipe or port. No. 5, like No. 1, is but very little worn, and serves particularly to emphasize the importance of having these valves made of the very best material. No. G speaks for itself. Plate 31. No. 1 shows a main piston-rod taken from a pump, broken at the upper end where the head was screwed on. No. 2 is a main valve rod and lower piston-valve, with an adjustable stop attached. It is evidently "home- made." If this adjustable stop should happen to be made a little too short, the main valve would travel too far down, the lower small packing-ring expand below the bushing, and the remainder of the trip have to be made with hand-brakes. Beware of adjustable stops. Plate 32. What an interesting trio we have in Plate 32. Nos. 1 and 2 are evidently the result of the coupling being caught and smashed between two cars. No. 3, it will be noted, has the upper lug bent downwards, a condition not infrequently resulting from a blow from a link or pin in the hands of some brakeman, in an attempt to stop a leak. Plate 33. No. 1 shows the body of a N. Y. triple valve, which has evidently received some ' 'hard knocks. ' ' No. 2 is a striking object lesson for the men who clean and repair Diseases of the Air Brake System. Ill triple-valves. The marks of the hammer clearly show the cause of the crack. When a gasket joint sticks persuasion generally works better than force in getting it loose. Plate 34. Nos. 1 and 2 are two triple valve pistons, on which the gum and dirt are "beautifully" shown. The smaller one, No. 2, was taken out of a freight triple on a car which came in with 4)^ -inch flat spots on eight wheels, because the brake ' 'stuck. ' ' The lot of emergency -valve gaskets, marked 3; show the effect of neglect and carelessness (particularly in the use of too much oil in the brake cylinder) and graphically illustrate a frequent cause of the ' 'blow from the triple- valve exhaust" about which we hear so much complaint. Plate 35. Plate 35, though not very beautiful, is exceedingly instructive. The sections of train-pipe shown were taken from under a refrigerator car, the pile of dirt numbered 2 being the accumulation shaken out of a piece only 8 feet long. Pile No. 1 was shaken out of a 16-foot length of new pipe, and most impressively teaches the need of blowing out all pipe thoroughly, in setting up new work, before connecting the valves. Plate 36. The triple screens shown in Plate 36 are fair samples of hundreds that are running at the present day. They are shown just as they were found. The two large, tin, Ajr^,. Plate 38 Plate 39 Plate 40 Diseases oj the Air Brake System. llo funnel-shaped extensions shown at one side were put on to hold the dirt found in the pipe next to the screen; the screens not being large enough to hold it all. The ac- cumulations are mostly a mixture of pipe, scale, cinders, sand, sponge, corn, etc. The effect of such a condition of affairs can be better appreciated when we reflect that all the air to operate the triple must pass through such a mass of dirt. With some of the samples shown a service application is still possible, but not an emergency stop. Plate 37. Plate 37 illustrates something similar to Plate 36, except that the case is a little more aggravated. No. 1 shows the check-valve case of a No. 1 New York triple- valve; No. 2 a pile of dirt taken from the train-pipe at the union connection, with the screen lying on top. Plate 38. To get some approximate idea of just how rapidly dirt will collect at the triple-valve screens, a dirt collector, in the form of a drain cup, with a strainer like the strainer in the supply -pipe to an injector, was placed on a number of cars just at the triple connection and the accumulations put in small bottles, which are shown in Plate 38. The amount in the ones numbered 2 and 3 does not show very clearly, so a short line has been drawn to one side of each to indicate the quantity. Plate 39. The attention of trainmen is particularly called to the exhibits shown in Plate 39. No. 1 is a retaining-valve with the exhaust hole plugged, and No. 2 is a retaining- 114 Diseases of the Air Brake System. valve pipe, which, because the valve was missing, was plugged with a piece of wood. Both of these were taken from cars on which the brake was reported "stuck," and had to be bled off after every application or else remained stuck all the time. From some imperfection in the quick-action part of the triple-valve there was a constant blow from the retaining- valve or pipe, which some uninstructed brakeman stopped in the manner shown. Plate 40. The most striking curiosity in the air-brake line the author has ever seen is illustrated in Plate 40. It is a car drain-cup, broken open to show the interior, into which some one has stuffed a heavy woolen cloth and pine stick, crushing the screen all to pieces, and almost completely filling the whole of the cavity. It was found just in the condition shown, when the brake came to be overhauled under a general order to examine all the drain-cups, and how it got into such a remarkable condi- tion is a mystery. It is possible some one tried to Clean out the cylindrical screen by forcing the woolen rag through with the stick, and that the stick became caught, and not being able to get it out, the pipe was coupled up in a hurry and nothing said about it. EVOLUTION OF THE AiR= Brake A BRIEF BUT COMPREHENSIVE HISTORY OF THE OTrVELOPMENT OF THE MODERN RAILROAD BRAKE, FROM THE EARLIEST CONCEPTION CONTAINED IN THE SIMPLE LEVER, UP TO, Ai^D INCLUDING, THE MOST APPROVED FORMS OF THE PRESENT DAY. PAUL SYNNESTVEDT Author of "Diseases of the Air Brake System," PUBLISHED BY 'LOCOMOTIVE :enginekring'» 256 Broadway, New York ;;9i^¥i^;%^i;;%*iS;?^^ wmmSmm^